While most Street analysts who follow the stock see little to worry about in the departure of Scott Forstall and retail stores chief John Browett, others are feeling unsettled about signs that the Apple product machinery is showing some un-Apple like signs of instability. The rejiggering of the management team follows a series of modest missteps:

Opening weekend iPhone 5 sales fell short of estimates.

The Apple maps app in iOS6 has been widely derided as inferior to Google Maps.

September quarter profits were shy of Street estimates.

The company warned that gross margins are going to fall sharply in the December quarter.

Also, iPad sales in the latest quarter were sell short of expectations.

The Street is not happy with the relatively high price of the iPad Mini, at $329 versus $199 for rival tablets from Google and Amazon and others.

This morning, reviews for the iPad Mini are generally positive, but some thing it is a shade too big - it won't fit in your pockets - and others are not happy with the lower resolution screen Apple is using compared to the larger iPad.

Signs of the crumbling of civilization? Well, no. But it all comes at a time when the company is being by bombarded by capable competitors in both the smartphone and tablet market. Microsoft is taking dead aim at the tablet opportunity in the enterprise; Steve Ballmer also noted this week that Windows 8 upgrade demand has been robust. There are improved handsets coming on the market from Samsung, Nokia and HTC and others.

Add it all up, and a management shift at Apple makes some observers wonder if the company is going to see tougher sledding from here.

AAPL is down $14.40, or 2.4%, to $589.60, the lowest level since late July.